Thermoreversible gelling starch and methods and uses related thereto

Abstract

The invention relates to cold-water soluble starch compositions having at least two mass fractions. The starch compositions of the invention are capable of thermoreversible gelation. The invention also relates, inter alia, to methods of manufacturing the starch composition of the invention, uses of said compositions, and compositions obtainable by the methods of the invention.

Description

[0001] P137948PC00

[0002] Title: THERMOREVERSIBLE GELLING STARCH AND METHODS AND USES

[0003] RELATED THERETO

[0004] FIELD

[0005] The invention relates to the field of food technology and starch applications. More in particular, it relates to cold-water soluble thermoreversible gelling starches.

[0006] BACKGROUND

[0007] Thermoreversible gelling starches represent a unique class of starch derivatives characterized by their ability to undergo reversible gelation in response to temperature fluctuations. These materials exhibit distinct rheological properties, allowing them to transition between sol and gel states, making them valuable for a wide range of applications in food science, pharmaceuticals, and industrial processes.

[0008] Starches are polysaccharides composed of glucose units linked primarily by a- 1,4 glycosidic bonds, and are widely used as thickeners, stabilizers, and gelling agents. Conventional starches typically form gels upon heating, but these gels are often irreversible upon cooling. In contrast, thermoreversible gelling starches maintain their gelling properties across multiple heating and cooling cycles, thus providing enhanced versatility in formulation and application.

[0009] The ability to manipulate the gelation and solubility of starches through temperature control opens up new avenues for product development. For example, in the food industry, thermoreversible gelling starches can be utilized in applications such as sauces, dressings, and desserts, where a desirable texture and mouthfeel are essential. Additionally, their utility extends to pharmaceutical formulations where controlled release and stability of active ingredients are critical.

[0010] Cold water soluble thermoreversible gelling starch, also known as instant thermoreversible gelling starch, is a specialized type of starch that can dissolve in cold water and quickly form a gel, either at ambient temperature or even below ambient temperature. This gel can then revert back to a liquid state upon heating, allowing for multiple cycles of gelation and liquefaction. Unlike traditional starches that require heat to dissolve, cold water soluble starches can readily dissolve in cold water, making them convenient for use in formulations without the need for cooking. These starches can easily dissolve in cold water, making them convenient for formulations without needing heating. Upon cooling or at ambient temperatures, these starches quickly form a gel, providing immediate viscosity and texture. The gels formed can be reverted back to a sol state upon heating, allowing for repeated use in temperature-controlled applications. It provides desirable textures, stability, and functionality in these formulations.

[0011] Overall, this type of starch offers significant advantages for applications requiring temperature-responsive behavior, flexibility in formulation, and ease of use. Instant thermoreversible gelling starches are suitable for various applications, including food products (e.g., sauces, dressings, desserts), pharmaceuticals, and cosmetics.

[0012] The production of instant thermoreversible gelling starch typically involves several steps. Starches are sourced from plants, such as com, tapioca, or potato starch. To achieve the desired properties, the native starch must undergo physical or chemical modifications. Thermoreversible starches are typically obtained via degradation, which is mostly chemical degradation e.g. acid or oxidative degradation, or enzymatical hydrolysis.

[0013] Oxidative degradation of starch refers to the chemical process in which starch is modified through the action of oxidizing agents (e.g. chlorine compounds, hydrogen peroxide, sodium hypochlorite) leading to changes in its molecular structure and properties. Oxidative degradation typically involves the introduction of oxygencontaining functional groups into the starch molecule, which can result in the cleavage of glycosidic bonds and the formation of smaller molecular fragments.

[0014] Acid degraded thermoreversible starch refers to a type of modified starch that has been treated with dilute acid (commonly hydrochloric acid or sulfuric acid) and heat it under controlled conditions to partially hydrolyze its molecular structure. The acid treatment breaks down some of the glycosidic bonds in the starch molecules, leading to shorter chains (oligosaccharides) and resulting in a starch that exhibits thermoreversible gelling properties. The process must be carefully monitored to achieve the desired level of degradation without completely hydrolyzing the starch. After the desired degradation is achieved, the acid must be neutralized, typically using a base such as sodium hydroxide, to ensure the starch is safe for use. The modified starch is purified to remove any residual acid and by-products, followed by drying to obtain a free-flowing powder. Preparing thermoreversible starches through enzymatic hydrolysis involves using specific enzymes such as a-amylase and glucoamylase to partially break down the starch molecules, resulting in starch that exhibits the desired thermoreversible gelling properties.

[0015] Drawbacks of these known methods for preparing thermoreversible starches include the following. First, large amounts of water are needed for solubilizing starch and diluting the acid / oxidizing agent or enzyme solutions. Second, the chemically or enzymatically degraded starch needs to be purified to remove any residual reactants, neutralizing agents and / or by-products. This requires filtration or centrifugation. Third, the drying process to reduce the large water volume after enzymatic or chemical starch hydrolysis consumes high amounts of energy. Fourth, chemically or enzymatically degraded starch may not meet the criteria for a "clean label" product, meaning it is not perceived as natural and free from synthetic additives or ingredients.

[0016] The present inventors aimed at overcoming at least some of the above drawbacks. In particular, they sought to provide a novel approach that is more sustainable e.g. requiring less solvent and extensive solvent removal than existing methods for producing an instant thermoreversible gelling starch, which ideally qualify as clean label starch products.

[0017] It was surprisingly found that this can be achieved by subjecting granular native starch to a controlled thermomechanical process, thereby degrading it to a desired level and obtain a specific molecular weight distribution which imparts the desired thermoreversible properties. For example, an instant gelling (cold water soluble) starch was obtained via a single-step extrusion which easily and quickly produce gels in water, with quick dissolution and no formation of lumps. Once firm gels were obtained, no signs of syneresis were observed. Thermoreversibility was confirmed with rheology tests.

[0018] A cold-water soluble thermoreversible gelling starch composition as herein disclosed is among others characterized by (i) an average molecular weight that is below and / or (ii) a poly dispersity above that of the starting material (i.e. the undegraded native granular starch) from which it was prepared. Interestingly, starch compositions showing desired thermoreversible gelling properties were found to display a unique average molecular weight distribution characterized by at least a high average molecular weight (Mwl) starch as main component and a lower average molecular weight (Mw2) starch as minor component. The Mwl starch represents a less degraded starch having a molecular weight of at most 80% of the starting material; and is considered to serve as a ‘’gelling component”, whereas the Mw2 starch having an average molecular weight below that of Mwl, e.g. 0.2 - 60 % of the starting material, represents a moderately degraded starch serving as an ‘’internal lubricating component”. Without wishing to be bound by any theory, it is conceivable that in the two distributions obtained via thermomechanical degradation, the longer, viscous less degraded polysaccharide chains are plasticized by the small distribution of the much shorter ones, once the gel would be heated up, allowing the sudden drop in viscosity typical of thermoreversible gels. Once cooled down again, the longer more viscous chains would re-entangle to form the gel again and entrapping the shorter ones which would be then adsorbing the free-water.

[0019] Hence, the invention provides a cold-water soluble thermoreversible gelling starch composition comprising a blend of a higher molecular weight gelling mass fraction (Mwl) and a lower molecular weight internal lubricant fraction (Mw2), which allows for (re)solubilization.

[0020] The sum of the starch mass fractions Mwl and Mw2 represent at least 50 wt.% of the total weight of the starch composition; and the mass ratio between the starch mass fractions Mwl and Mw2 is 1.1 : 1 - 20 : 1. Furthermore, the poly dispersity within mass fractions Mwl and Mw2 is relatively low (typically in a range of from 1.0 - 1.7), whereas the overall poly dispersity of the composition is broad (typically at least 2, preferably in a range of from 1.4 to 6.2, more preferably of from 2 to 5).

[0021] These products are herein referred also to as thermoreversible extruded starches or ‘’TRES”. The TRES concept obviates the need for pretreatment, high amounts of water, and / or chemicals such as acids, and is therefore highly sustainable and economically attractive process.

[0022] Hence, in a preferred embodiment the cold-water soluble thermoreversible gelling starch composition is free of additives traditionally used in starch extrusion, such as a gas-forming or gas-generating agent, e.g. carbonate salt, an organic or inorganic acid or an acid-supplying substance. Accordingly, in one aspect the invention provides a cold-water soluble thermoreversible gelling starch composition comprising at least two mass fractions Mwl and Mw2 of different average molecular weight, in which a) Mw2 < Mwl < MwO, MwO being defined as the average molecular weight of the native granular starch from which the cold-water soluble thermoreversible gelling starch composition was prepared; b) mass fraction Mwl has an average molecular weight of at most 80 % of MwO; c) the sum of the mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the cold-water soluble thermoreversible gelling starch composition; and d) the mass ratio between the mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1.

[0023] In another aspect is also provided is a cold-water soluble thermoreversible gelling starch composition comprising at least two starch mass fractions Mwl and Mw2 of different average molecular weight, in which a) mass fraction Mwl has an average molecular weight in a range of from 12000 to 36000 kDa, preferably of from 13000 to 35000 kDa; more preferably of from 17000 to 32000 kDa; b) mass fraction Mw2 has an average molecular weight in a range of from 700 to 3000 kDa; preferably of from 750 to 2500 kDa; c) the sum of the starch mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the cold-water soluble thermoreversible gelling starch composition; and d) the mass ratio between the starch mass fractions Mwl and Mw2 is 1.1 : 1 - 20 : 1.

[0024] LEGEND TO THE FIGURE

[0025] Figure 1 : Rheology plots showing thermoreversible properties of exemplary extruded potato starch compositions (samples 1, 7 and 12 of Table 6). Squares indicate the Storage modulus G’ (Pa) and triangles indicate the Loss modulus G” (Pa).

[0026] DETAILED DESCRIPTION

[0027] A cold-water soluble thermoreversible gelling starch composition of the present invention is among others characterized by (i) an average molecular weight that is below and / or (ii) a poly dispersity above that of the starting material (i.e. the undegraded native granular starch) from which it was prepared.

[0028] Herein, “cold water soluble” or “cold-water soluble” means that the composition readily dissolves in water of ambient temperature, viz. of about 15-25 °C. Preferably, a cold-water soluble composition has a solubility of at least 0.01 wt% in water of 25 °C, more preferably a solubility in a range of from 0.01 to 35 wt% in water of 25 °C, wherein preferably the water is demineralized water. Herein, “cold-water soluble” may be used interchangeably with “cold-water swellable”. Preferably, a cold-water swellable composition does not form a precipitate if the composition is present in water of 25 °C at a concentration of at least 0.01 wt%, preferably of from 0.01 to 35 wt%, as compared to the combined weight of the water and the composition, wherein preferably the water is demineralized water.

[0029] Herein, “dispersity” and “polydispersity” are used interchangeably, and in line with their normal meaning in the art. As such, as used herein the dispersity (Dn, in literature also “D”), also known as the poly dispersity index (PDI) or heterogeneity index, is a measure of the distribution of molecular mass in a given polymer sample, in the present case of polysaccharides in a starch composition. The Dn of a polymer equals Mw / Ma, wherein M is the weight average molecular weight and Mnis the number average molecular weight. The Mw and Mnof a composition or a mass fraction of a composition can be determined using standard techniques in the art. For example, M\v can be determined by, inter alia, static light scattering, small angle neutron scattering, X-ray scattering, and sedimentation velocity. Likewise, Mncan for example be determined using, inter alia, gel permeation chromatography, viscometry via the Mark-Houwink equation, colligative methods such as vapor pressure osmometry, end-group determination or proton NMR.

[0030] In particular, molecular weight analyses can be performed with Size Exclusion (SEC) Chromatography with a Multi-angle laser light scattering (MALLS) in combination with a Refractive Index (RI) detector. MALLS in combination with RI allows for absolute determination of the molar mass and size of macromolecules and nanoparticles in solution, offering the highest sensitivity and widest range of molecular weight, size and concentrations. It is most often used in conjunction with SEC Chromatography to determine distributions of mass, size and composition independent of column calibration by reference standards.

[0031] Unless indicated otherwise, “average molecular weight” or “MWavg” as used herein refers to Mw, viz. the weight average molecular weight.

[0032] Unless indicated otherwise, “wt%” as used herein refers to the weight percentage as compared to the dry weight of the composition.

[0033] MwO as used herein refers to the average molecular weight of the native granular starch from which the cold-water soluble thermoreversible gelling starch composition was prepared.

[0034] In one aspect, mass fraction Mwl has an average molecular weight of at most 79%, at most 78%, at most 77%, at most 76%, at most 75%, at most 76%, at most 75%, at most 74%, at most 73%, at most 72%, at most 71%, or at most 70% of MwO.

[0035] In further preferred embodiments, mass fraction Mwl has an average molecular weight of at most 65 % of MwO, more preferably at most 60 %, at most 55 %, at most 50 %, at most 45 %, at most 40 %, at most 39 %, at most 38 %, at most 37 %, at most 36 %, at most 35 %, or at most 34 % of MwO.

[0036] In some embodiments, mass fraction Mwl has an average molecular weight of at least 5 % of MwO, preferably at least 7 %, at least 10 %, at least 12 %, at least 14 %, at least 16 %, at least 18 %, at least 20 %, at least 22 %, at least 24 %, or at least 25 % of MwO. Preferably, mass fraction Mwl has an average molecular weight in a range of from 2 to 80 % of MwO, more preferably of from 3 to 60%, more preferably of from 4 to 45%, and most preferably of from 5 to 35%.

[0037] In a composition of the invention, Mwl is less than MwO, and Mw2 is less than Mwl. Suitably, Mw2 has an average molecular weight of 0.2 - 60 % of MwO, preferably 0.4 to 40% of MwO, more preferably from 0.5 to 15%, even more preferably from 0.6 to 5%, and most preferably of from 0.7 to 2.5% of MwO.

[0038] Alternatively or additionally mass fraction Mw2 has an average molecular weight of at most 20 % of MwO, preferably at most 18 %, at most 16 %, at most 14 %, at most 12 %, at most 11 %, at most 10 %, at most 9 %, at most 8%, or at most 7 %, of Mwl and / or mass fraction Mw2 has an average molecular weight of at least 2 % of Mwl, preferably at least 3 %, at least 4 %, at least 5 %, at least 6 %, at least 7 %, at least 8 %, at least 9 %, at least 10 % of Mwl.

[0039] Preferably, Mw2 has an average molecular weight of 1 - 70 % of Mwl, preferably 2 to 50% of Mwl, more preferably from 3 to 30% of Mwl, even more preferably from 3.5 to 20%, and most preferably from 4.0 to 15% of Mwl.

[0040] As will be understood by a person skilled in the art, the absolute average molecular weight values of the different fractions will depend on the type of granular starch used as starting material. Preferably, the native granular starch from which the cold-water soluble thermoreversible gelling composition was prepared comprises:

[0041] (i) a waxy potato starch, characterized by an MwO of 100 000 kDa ± 10 000 kDa, preferably about 100 223 kDa;

[0042] (ii) a native potato starch, characterized by an MwO of 450 000 kDa ± 45 000 kDa, preferably about 443 847 kDa;

[0043] (iii) a waxy tapioca starch, characterized by an MwO of 270 000 kDa ± 27 000 kDa, preferably about 270 000 kDa;

[0044] (iv) a native faba starch, characterized by an MwO of 150 000 kDa ± 15 000 kDa, preferably about 152 000 kDa; and / or

[0045] (v) a native pea starch, characterized by an MwO of 330 000 ± 33 000 kDa, preferably about 328 000 kDa.

[0046] More preferably, the native granular starch from which the cold-water soluble thermoreversible gelling composition was prepared comprises:

[0047] (i) a waxy potato starch, characterized by an MwO of 100 000 kDa ± 10 000 kDa, preferably about 100 223 kDa;

[0048] (iii) a waxy tapioca starch, characterized by an MwO of 270 000 kDa ± 27 000 kDa, preferably about 270 000 kDa;

[0049] (iv) a native faba starch, characterized by an MwO of 150 000 kDa ± 15 000 kDa, preferably about 152 000 kDa; and / or

[0050] (v) a native pea starch, characterized by an MwO of 330 000 ± 33 000 kDa, preferably about 328 000 kDa.

[0051] In one embodiment, the invention provides a cold water soluble thermoreversible gelling starch composition, e.g. derived from a waxy com, tapioca or potato starch, wherein mass fraction Mwl has an average molecular weight in a range of from 12 000 to 36 000 kDa, preferably of from 13000 to 35000 kDa.

[0052] In some embodiments, at least about the average molecular weight of Mwl is at least about 13 500, at least about 14 000, at least about 15 000, at least about 16 000, at least about 17 000, at least about 18 000, at least about 19 000, at least about 20 000, at least about 21 000, at least about 22 000, at least about 23 000, at least about 24 000, at least about 25 000, at least about 26 000, at least about 27 000, at least about 28 000, at least about 29 000, at least about 30 000, at least about 31 000, at least about 32 000, or at least about 33 000 kDa. In some embodiments, the average molecular weight of Mwl is at most about 34 500, at most about 34 000, at most about 33 000, at most about 32 000, at most about 31 000, at most about 30 000, at most about 29 000, at most about 28

[0053] 000, at most about 27 000, at most about 26 000, at most about 25 000, at most about 24

[0054] 000, at most about 23 000, at most about 22 000, at most about 21 000, at most about 20

[0055] 000, at most about 19 000, at most about 18 000, at most about 17 000, at most about 16

[0056] 000, at most about 15 000, or at most about 14 000 kDa.

[0057] Exemplary ranges of the average molecular weight of Mwl include of from 17 000 to 34 000 kDa, from 18 000 to 32 000 kDa, from 18 000 to 30 000 kDa, from 16 000 to 29 000 kDa, from 14 000 to 24 000 kDa, from 14 000 to 23 000 kDa, from 16 000 to 24 000 kDa, from 19 000 to 26 000 kDa, from 22 000 to 34 000 kDa, from 22 000 to 30 000 kDa, from 24 000 to 31 000 kDa, from 25 000 to 29 000 kDa, from 20 000 to 26 000 kDa, , and from 12 500 kDa to 15 000 kDa.

[0058] Typically, the poly dispersity Dn within mass fraction Mwl is in the range of from 1.0 - 1.7, preferably 1.1 - 1.4, more preferably 1.2 - 1.4. For example, Dn of mass fraction Mwl is 1.2, 1.3 or 1.4.

[0059] In one embodiment, the invention provides a cold water soluble thermoreversible gelling starch composition, wherein mass fraction Mw2 has an average molecular weight in a range of from 700 to 3500 kDa, preferably of from 700 to 3000 kDa, more preferably of from 750 to 2500 kDa. In some embodiments, the average molecular weight of Mw2 is at least about 700, at least about 750, at least about 800, at least about 900, at least about 1000, at least about 1100, at least about 1200, at least about 1300, at least about 1400, at least about 1500, at least about 1600, at least about 1700, at least about 1800, at least about 1900, at least about 2000, at least about 2100, at least about 2200, at least about 2300, at least about 2400, at least about 2500, at least about 2600, at least about 2700, at least about 2800, at least about 2900, or at least about 3000 kDa. In some embodiments, the average molecular weight of Mw2 is at most about 3400, at most about 3300, at most about 3200, at most about 3100, at most about 3000, at most about 2900, at most about 2800, at most about 2700, at most about 2600, at most about 2500, at most about 2400, at most about 2300, at most about 2200, at most about 2100, at most about 2000, at most about 1900, at most about 1800, at most about 1700, at most about 1600, at most about 1500, at most about 1400, at most about 1300, at most about 1200, at most about 1100, at most about 1000, or at most about 950 kDa.

[0060] Exemplary ranges of the average molecular weight of Mw2 include of from 800 to 3400 kDa, from 800 to 3200 kDa, from 800 to 3000 kDa, from 900 to 2900 kDa, from 900 to 2500 kDa, from 900 to 2000 kDa, from 900 to 1800 kDa, from 1000 to 3000 kDa, from 1000 to 2600 kDa, from 1000 to 24000 kDa, from 1200 to 2700 kDa, from 1200 to 2500 kDa, from 800 to 2300, from 1400 to 3200, from 800 to 1500 kDa, from 1500 to 3200 kDa, from 1200 to 2000 kDa, from 1500 to 2000 kDa, from 1700 to 2700 kDa, and from 700 to 900 kDa.

[0061] Typically, the poly dispersity within mass fraction Mw2 is in the range of 1.0 - 1.4, preferably 1.1 - 1.4, more preferably 1.1 - 1.3. For example, the Dn of mass fraction Mw2 is 1.1, 1.2 or 1.3.

[0062] The cold water soluble thermoreversible gelling starch composition as a whole may have an average molecular weight in a range of from 13000 to 33000 kDa. It will be understood that herein, the average molecular weight of the composition of the invention as a whole may be referred to as “MwTot”. In some embodiments, the average molecular weight of the starch composition of the invention as a whole is at least about 13 500, at least about 14 000, at least about 15 000, at least about 16 000, at least about 17 000, at least about 18 000, at least about 19 000, at least about 20 000, at least about 21 000, at least about 22 000, at least about 23 000, at least about 24 000, at least about 25 000, at least about 26 000, at least about 27 000, at least about 28 000, or at least about 30 000 kDa. In some embodiments, the average molecular weight of the starch composition of the invention as a whole is at most about 32 000, at most about 31

[0063] 000, at most about 30 000, at most about 29 000, at most about 28 000, at most about 27

[0064] 000, at most about 26 000, at most about 25 000, at most about 24 000, at most about 23

[0065] 000, at most about 22 000, at most about 21 000, at most about 20 000, at most about 19 000, at most about 18 000, at most about 17 000, at most about 16 000, or at most about 15 000 kDa.

[0066] Exemplary ranges for the average molecular weight of the starch composition of the invention as a whole include of from 13 000 to 34 000 kDa, from 14 000 to 32 000 kDa, from 14 000 to 30 000 kDa, from 14 000 to 29 000 kDa, from 15 000 to 29 000 kDa, from 16 000 to 28 000 kDa, from 16 000 to 26 000 kDa, from 17 000 to 30 000 kDa, from 20 000 to 35 000 kDa, from 13 000 to 20 000 kDa, from 13 000 to 27 000 kDa, from 13 000 to 25 000 kDa, from 17 000 to 27 000, from 17 000 to 26 000, from 18 000 to 25 000 kDa, from 19 000 to 32 000 kDa, from 20 000 to 28 000 kDa, from 22 000 to 27 000 kDa, from 24 000 to 29 000 kDa, from 25 000 to 30 000 kDa, from 20 000 to 25 000 kDa and from 16 000 to 27 000 kDa.

[0067] The average poly dispersity of the cold-water soluble thermoreversible gelling starch composition as a whole is higher than the poly dispersity of the at least two starch mass fractions Mwl and Mw2. It will be understood that herein, the average poly dispersity of the starch composition of the invention as a whole may be referred to as “Dn avg” or “Dn overall”. Preferably, the cold-water soluble thermoreversible gelling starch composition as a whole has an average poly dispersity in a range of from 1.4 to 6.2, preferably of from 1.5 to 6.0, more preferably of from 1.6 to 5.0, more preferably still of from 2.2 to 4.8, and even more preferably of from 2.2 to 4.4. In some embodiments, the average poly dispersity of the composition of the invention as a whole is at least about 1.4, at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8, at least about 1.9, at least about 2.0, at least about 2.1, at least about 2.2, at least about 2.3, at least about 2.4, at least about 2.5, at least about 2.6, at least about 2.7, at least about 2.8, at least about 2.9, at least about 3.0, at least about 3.1, at least about 3.2, at least about 3.3, at least about 3.4, at least about 3.5, at least about 3.6, at least about 3.7, at least about 3.8, at least about 3.9, at least about 4.0, at least about 4.1, at least about 4.2, at least about 4.3, at least about 4.4, at least about 4.5, at least about 4.6, or at least about 4.7. In some embodiments, the average poly dispersity of the composition of the invention as a whole is at most about 6.2, at most about 6.1, at most about 6.0, at most about 5.9, at most about 5.8, at most about 5.7, at most about 5.6, at most about 5.5, at most about 5.4, at most about 5.3, at most about 5.2, at most about 5.1, at most about 5.0, at most about 4.9, at most about 4.8, at most about 4.7, at most about 4.6, at most about 4.5, at most about 4.4, at most about 4.5, at most about 4.4, at most about 4.3, at most about 4.2, at most about 4.1, at most about 4.0, at most about 3.9, at most about 3.8, at most about 3.7, at most about 3.6, at most about 3.5, at most about 3.4, at most about 3.3, at most about 3.2, at most about 3.1, or at most about 3.0. Preferably, the overall poly dispersity of exemplary starch compositions of the invention is in a range of from 1.6 to 3.0, 2.2 to 4.0, 2.2 to 3.5, 2.0 to 5.0, 2.2 to 4.8, 2.4 to 4.8, 2.8 to 5.0, 3.0 to 4.8, 4.0 to 4.8 or 4.3 to 4.8.

[0068] Any of the ranges, upper and lower limit values as mentioned herein, in particular in relation to average molecular weight or polydispersity (Dn), may be combined.

[0069] Exemplary compositions can be characterized as follows:

[0070] • Mwl has an average molecular weight in a range of from 14 000 kDa to 34 000 kDa; Mw2 has an average molecular weight in a range of from 800 to 2300 kDa; MwTot in the range of from 13000 to 32000 kDa; Dn of mass fraction Mwl in the range of 1.2 to 1.4; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and / or Dn overall in the range of 1.6 to 4.8.

[0071] • Mwl has an average molecular weight in the range of from 17 000 kDa to 34 000 kDa; Mw2 has an average molecular weight in the range of from 800 to 2300 kDa; MwTot in the range of from 14 000 to 32 000 kDa; Dn of mass fraction Mwl in the range of 1.2 to 1.4; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and / or Dn overall in the range of 2.4 to 4.8.

[0072] • Mwl has an average molecular weight in the range of from 19 000 kDa to 34 000 kDa; Mw2 has an average molecular weight in the range of from 900 to 2300 kDa; MwTot in the range of from 16 000 to 32 000 kDa; Dn of mass fraction Mwl in the range of 1.2 to 1.4; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and / or Dn overall in the range of 2.4 to 4.5.

[0073] • Mwl has an average molecular weight in the range of from 16 000 kDa to 20 000 kDa; Mw2 has an average molecular weight in the range of from 1400 to 1900 kDa; MwTot in the range of from 14 000 to 18 000 kDa; Dn of mass fraction Mwl in the range of 1.1 to 1.2; Dn of mass fraction Mw2 in the range of 1.1 to 1.2; and / or Dn overall in the range of 2.2 to 2.4.

[0074] • Mwl has an average molecular weight in the range of from 28 000 kDa to 29 000 kDa; Mw2 has an average molecular weight in the range of from 1900 to 2500 kDa; MwTot in the range of from 25 000 to 27 000 kDa; Dn of mass fraction Mwl in the range of 1.6 to 1.7; Dn of mass fraction Mw2 in the range of 1.1 to 1.2; and / or Dn overall in the range of 2.5 to 3.0.

[0075] • Mwl has an average molecular weight in the range of from 12 500 kDa to 13 500 kDa; Mw2 has an average molecular weight in the range of from 700 to 800 kDa; Dn of mass fraction Mwl in the range of 1.3 to 1.5; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and / or Dn overall in the range of 5.7 to 6.1; and optionally the cold-water thermoreversible gelling starch composition comprises a third mass fraction Mw3, wherein Mw3 has an average molecular weight in the range of from 130 000 kDa to 140 000 kDa; and the Dn of mass fraction Mw3 is in a range of from 1.9 to 2.3.

[0076] • Mwl has an average molecular weight in the range of from 13 700 kDa to 14 700 kDa; Mw2 has an average molecular weight in the range of from 800 to 900 kDa; Dn of mass fraction Mwl in the range of 1.3 to 1.5; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and / or Dn overall in the range of 5.7 to 6.1; and optionally the cold-water thermoreversible gelling starch composition comprises a third mass fraction Mw3, wherein Mw3 has an average molecular weight in the range of from 128 000 kDa to 138 000 kDa; and the Dn of mass fraction Mw3 is in a range of from 1.8 to 2.2.

[0077] Preferably, the exemplary compositions can be characterized as follows:

[0078] • Mwl has an average molecular weight in a range of from 14 000 kDa to 34 000 kDa; Mw2 has an average molecular weight in a range of from 800 to 2300 kDa; MwTot in the range of from 13 000 to 32 000 kDa; Dn of mass fraction Mwl in the range of 1.2 to 1.4; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and Dn overall in the range of 1.6 to 4.8.

[0079] • Mwl has an average molecular weight in the range of from 17 000 kDa to 34 000 kDa; Mw2 has an average molecular weight in the range of from 800 to 2300 kDa; MwTot in the range of from 14 000 to 32 000 kDa; Dn of mass fraction Mwl in the range of 1.2 to 1.4; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and Dn overall in the range of 2.4 to 4.8.

[0080] • Mwl has an average molecular weight in the range of from 19 000 kDa to 34 000 kDa; Mw2 has an average molecular weight in the range of from 900 to 2300 kDa; MwTot in the range of from 16 000 to 32 000 kDa; Dn of mass fraction Mwl in the range of 1.2 to 1.4; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and Dn overall in the range of 2.4 to 4.5.

[0081] • Mwl has an average molecular weight in the range of from 16 000 kDa to 20 000 kDa; Mw2 has an average molecular weight in the range of from 1400 to 1900 kDa; MwTot in the range of from 14 000 to 18 000 kDa; Dn of mass fraction Mwl in the range of 1.1 to 1.2; Dn of mass fraction Mw2 in the range of 1.1 to 1.2; and Dn overall in the range of 2.2 to 2.4.

[0082] • Mwl has an average molecular weight in the range of from 28 000 kDa to 29 000 kDa; Mw2 has an average molecular weight in the range of from 1900 to 2500 kDa; MwTot in the range of from 25 000 to 27 000 kDa; Dn of mass fraction Mwl in the range of 1.6 to 1.7; Dn of mass fraction Mw2 in the range of 1.1 to 1.2; and Dn overall in the range of 2.5 to 3.0.

[0083] • Mwl has an average molecular weight in the range of from 12 500 kDa to 13 500 kDa; Mw2 has an average molecular weight in the range of from 700 to 800 kDa; Dn of mass fraction Mwl in the range of 1.3 to 1.5; Dn of mass fraction Mw2 in the range of 1.1 to 1.3; and Dn overall in the range of 5.7 to 6.1. • Mwl has an average molecular weight in the range of from 13 700 kDa to 14 700 kDa; Mw2 has an average molecular weight in the range of from 800 to 900 kDa; Dn of mass fraction Mwl in the range of 1.3 to 1.5; Dn of mass fraction Mw2 in the range of

[0084] 1.1 to 1.3; and Dn overall in the range of 5.7 to 6.1.

[0085] • Mwl has an average molecular weight in the range of from 12 500 kDa to 13 500 kDa; Mw2 has an average molecular weight in the range of from 700 to 800 kDa; Dn of mass fraction Mwl in the range of 1.3 to 1.5; Dn of mass fraction Mw2 in the range of

[0086] 1.1 to 1.3; and / or Dn overall in the range of 5.7 to 6.1; and the cold-water thermoreversible gelling starch composition comprises a third mass fraction Mw3, wherein Mw3 has an average molecular weight in the range of from 130 000 kDa to 140 000 kDa; and the Dn of mass fraction Mw3 is in a range of from 1.9 to 2.3.

[0087] • Mwl has an average molecular weight in the range of from 13 700 kDa to 14 700 kDa; Mw2 has an average molecular weight in the range of from 800 to 900 kDa; Dn of mass fraction Mwl in the range of 1.3 to 1.5; Dn of mass fraction Mw2 in the range of

[0088] 1.1 to 1.3; and / or Dn overall in the range of 5.7 to 6.1; and the cold-water thermoreversible gelling starch composition comprises a third mass fraction Mw3, wherein Mw3 has an average molecular weight in the range of from 128 000 kDa to 138 000 kDa; and the Dn of mass fraction Mw3 is in a range of from 1.8 to 2.2.

[0089] The sum of the starch mass fractions Mwl and Mw2 represents at least 50 wt.% of the dry weight of the cold-water soluble thermoreversible gelling starch composition. For example, at least 55 wt%, at least 58, at least 60, at least 62, at least 64, at least 68, at least 70, at least 72, at least 74, at least 76, at least or 78 wt% of the total weight of the cold-water soluble thermoreversible gelling starch composition consists of mass fractions Mwl and Mw2.

[0090] In a specific aspect, mass fractions Mwl and Mw2 together constitute at least 80 wt% of the dry weight of the composition, preferably at least 85 wt%, more preferably at least 90 wt%, even more preferably at least 95 wt%, and most preferably at least 99 wt%. The mass ratio between the starch mass fractions Mwl and Mw2 is in the range of from 1.1 : 1 to 20 : 1. Typically, mass fraction Mwl is the major (i.e. more abundant) fraction. Hence, in one embodiment the mass ratio between Mwl and Mw2 is in the range of from 2 : 1 to 20 : 1, 3: 1 to 20: 1, 5: 1 to 20: 1, 6: 1 to 20: 1 or 7: 1 to 20: 1, 3 : 1 to 15 : 1, 4 : 1 to 14: 1, 5: 1 to 13: 1, 4: 1 to 13: 1 or 5: 1 to 11 : 1.

[0091] Particularly good results, e.g. when used as gelatin replacer in a food item, can be obtained if Mwl represents at least 80 wt%, at least 82 wt%, at least 84 wt%, at least 85 wt%, at least 86 wt%, at least 87 wt%, at least 88 wt%, at least 89 wt%, at least 90 wt%, at least 91 wt% or at least 92 wt% of the composition, and / or wherein Mw2 represents up to 17 wt%, up to 16 wt%, up to 15 wt%, up to 14 wt%, up to 13 wt%, up to 12 wt%, up to 11 wt%, up to 10 wt%, up to 9 wt%, up to 8 wt% or up to 7 wt% of the composition.

[0092] In some preferred embodiments, the cold-water thermoreversible gelling starch composition comprises a third mass fraction Mw3. Preferably, the average molecular weight of the mass fractions is Mw2 < Mwl < Mw3 < MwO. Preferably, mass fraction Mw3 has an average molecular weight of at most 95% of MwO, more preferably at most 90% of MwO. Preferably, the average molecular weight of Mw3 is in a range of from 30 to 95% of MwO, more preferably of from 35 to 90% of MwO. Preferably, the average molecular weight of Mw3 is in a range of from 120 000 kDa to 150 000 kDa, more preferably of from 125 000 to 145 000 kDa, even more preferably of from 127 500 kDa to 140 000 kDa, and most preferably from 130 000 to 135 000 kDa. Preferably, the mass ratio between mass fractions Mwl and Mw3 are in a range of from 30: 1 to 60: 1, more preferably of from 35: 1 to 50: 1. Preferably, the mass ratio between mass fractions Mw2 and Mw3 are in a range of from 5: 1 to 25: 1, more preferably of from 10: 1 to 20: 1. Preferably, Mw3 constitutes at most 5 wt% of the dry weight of the composition, more preferably at most 4 wt%, even more preferably at most 3 wt%, and most preferably at most 2 wt% of the dry weight of the cold-water thermoreversible gelling starch composition. Preferably, mass fractions Mwl, Mw2, and Mw3 together constitute at least 85 wt% of the dry weight of the cold-water thermoreversible gelling starch composition, more preferably at least 90 wt%, even more preferably at least 95 wt%, and most preferably at least 99 wt%. Preferably the Dn of Mw3 is in a range of from 1.5 to 2.5, more preferably of from 1.7 to 2.3, and most preferably of from 1.9 to 2.2. Preferably, the cold-water thermoreversible gelling starch composition comprises a third mass fraction Mw3, wherein the average molecular weight of the mass fractions is Mw2 < Mwl < Mw3 < MwO; mass fraction Mw3 has an average molecular weight of at most 95% of MwO, more preferably at most 90% of MwO; the average molecular weight of Mw3 is in a range of from 30 to 95% of MwO, more preferably of from 35 to 90% of MwO; the average molecular weight of Mw3 is in a range of from 120 000 kDa to 150 000 kDa, more preferably of from 125 000 to 145 000 kDa, even more preferably of from 127 500 kDa to 140 000 kDa, and most preferably from 130 000 to 135 000 kDa; the mass ratio between mass fractions Mwl and Mw3 are in a range of from 30: 1 to 60: 1, more preferably of from 35: 1 to 50: 1; the mass ratio between mass fractions Mw2 and Mw3 are in a range of from 5: 1 to 25: 1, more preferably of from 10: 1 to 20: 1; Mw3 constitutes at most 5 wt% of the dry weight of the composition, more preferably at most 4 wt%, even more preferably at most 3 wt%, and most preferably at most 2 wt% of the dry weight of the cold-water thermoreversible gelling starch composition; mass fractions Mwl, Mw2, and Mw3 together constitute at least 85 wt% of the dry weight of the cold-water thermoreversible gelling starch composition, more preferably at least 90 wt%, even more preferably at least 95 wt%, and most preferably at least 99 wt%; and the Dn of Mw3 is in a range of from 1.5 to 2.5, more preferably of from 1.7 to 2.3, and most preferably of from 1.9 to 2.2.

[0093] In one embodiment, a cold-water soluble thermoreversible gelling starch composition of the invention is prepared by thermomechanical degradation of a tuberous starch or a root starch. Hence, provided is a cold-water soluble thermoreversible gelling starch composition wherein mass fractions Mwl and Mw2 are of tuberous or root starch origin. Preferably, mass fractions Mwl and Mw2 are of tuberous or root starch origin comprising at least 55 wt% of amylopectin, preferably at least 60 wt% of amylopectin, more preferably at least 65 wt%, more preferably at least 70 wt%, more preferably at least 72 wt%, more preferably at least 75 wt%. Without wishing to be bound by theory, the highly branched structure of glucose polymers in amylopectin starch is considered to contribute to obtaining a better thermoreversible gel. Because smaller amylopectin chains are not linear (as in amylose), this is believed to increase their plasticizing effect due to their larger hindrance, thereby decreasing viscosity when compared to amylose chains which tend to form more viscous entanglements.

[0094] In principle, any type of starch can be used in the invention, but it is preferred that starch with at least about 55 wt%, at least about 60 wt%, more preferably at least 65 wt%, more preferably at least about 70 wt%, amylopectin is used.

[0095] Preferably, the native granular starch used in the invention to provide cold-water soluble thermoreversible gelling starch compositions of the invention is selected from the group consisting of corn starch, potato starch, tapioca starch, wheat starch, faba starch, pea starch, arrowroot starch, and combinations thereof; wherein preferably the starch is potato starch, tapioca starch, pea starch, faba starch, or a combination thereof. In particularly preferred embodiments, the native granular starch used in the invention to provide cold-water soluble thermoreversible gelling starch compositions of the invention is a waxy starch, preferably waxy potato starch, waxy tapioca starch, or a combination thereof; and most preferably the starch is waxy potato starch.

[0096] Consequently, it is preferred that both mass fractions Mwl and Mw2 comprise a starch selected from the group consisting of com starch, potato starch, tapioca starch, wheat starch, faba starch, pea starch, arrowroot starch, and combinations thereof; wherein preferably the starch is potato starch, tapioca starch, pea starch, faba starch, or a combination thereof; more preferably the starch is waxy potato starch, waxy tapioca starch, or a combination thereof; and most preferably the starch is waxy potato starch.

[0097] In a particularly preferred embodiment, the Mwl and Mw2 starch fractions are a waxy starch. Waxy starch refers to a type of starch that is almost entirely (about 98 or 99 wt%) composed of amylopectin, with little to no amylose. This unique composition gives waxy starches distinct properties compared to regular starches, which typically contain both amylose and amylopectin. The waxy starch is suitably selected from the group consisting of potato starch, tapioca starch, com starch, faba starch, pea starch, arrowroot starch, and any combination thereof. Preferably, the waxy starch is waxy potato starch.

[0098] As will be appreciated by a person skilled in the art, a cold water soluble thermoreversible gelling starch composition according to the invention is readily obtained by physical processing, obviating the need for chemicals such as oxidizing agents or any other type of chemical modification of the starch components. Accordingly, in one embodiment said starch composition comprises or consists of starch components that have not been chemically modified. Such compositions can be marketed as “clean label starch”. A clean label starch composition refers to starch that is natural or minimally processed, without synthetic chemicals or additives, and is labeled in a transparent, consumer-friendly way. It meets the growing demand for simpler, more recognizable ingredients while maintaining the functional benefits of starch in food products. Moreover, the reduction or avoidance of the use of chemicals is also an advantage of clean label starches.

[0099] Further products, uses and applications

[0100] A cold water-soluble, thermoreversible gelling starch composition as provided herein has unique properties that make it suitable for specialized food and non-food applications. Cold water-soluble, thermoreversible gelling starch compositions of the invention have a wide range of applications due to their ability to gel at cold temperatures and reverse to liquid form with heat. They are particularly useful in food products (instant foods, desserts, sauces), pharmaceuticals (drug delivery, for example capsules), cosmetics (creams, gels), and industrial uses (adhesives, textiles, and packaging). This combination of cold water solubility and thermoreversible properties allows for flexibility in product formulation, easy processing, and enhanced consumer convenience.

[0101] The invention therefore also relates to a consumer product or an industrial product comprising a cold-water soluble thermoreversible gelling starch composition according to the invention. For example, provided herein is a food item, a feed item, a thickening agent, an adhesive, a cosmetic product, paper, or a construction material, comprising a cold-water soluble thermoreversible gelling starch composition as herein disclosed. Furthermore, the invention relates to the use of a cold-water soluble thermoreversible gelling starch composition according to the invention as a (clean label) food ingredient, a feed ingredient, a thickening agent, an adhesive agent, an ingredient for a cosmetic product, a gelling agent, a pectin replacer, a gelatin replacer. Also provided is the use of a cold-water soluble thermoreversible gelling starch composition, as an ingredient for the production of paper, and / or as a component of a construction material.

[0102] In one embodiment, the invention provides the use of a (clean label) cold water- soluble, thermoreversible gelling starch composition in the food industry, for example in instant or no-cook food items. Also provided is a food item comprising a (clean label) cold water-soluble, thermoreversible gelling starch composition. Because this starch dissolves and gels in cold water, it can add thickness and viscosity to refrigerated dressings without the need for cooking. For example, it is ideal for applications like instant puddings or desserts, or in cold-prepared salad dressings and dips. Other applications include instant soups and sauces, and bakery fillings and glazes. It is advantageously used in fillings where repeated heating and cooling may occur. The thermoreversible gel allows for a smooth texture that reforms after cooling.

[0103] In a specific aspect, it is used in a confectionery product. For example, cold water- soluble, thermoreversible starches are valuable in gummy candies or jellies because it creates a gel that can melt and reform depending on temperature. They provide a clean, smooth texture with the ability to reverse back into liquid form when heated. Alternatively, they can improve texture and stability in frozen desserts like ice cream or frozen yogurts by creating a stable, creamy consistency that maintains gel integrity even after freezing and thawing. Still further food applications include meat and fish products. In applications like processed meats, the starch provides cold-binding properties and retains moisture, improving the texture and stability of the product. In one embodiment, the invention provides the use of a cold-water soluble thermoreversible gelling composition as a food ingredient, thickening agent, and / or (vegan) gelatin replacer. Furthermore, starch compositions of the invention can be used in dairy products, such as yogurt.

[0104] As there is also a strong desire to provide more plant-based products, especially from an environmental perspective, it is an additional advantage of products of the invention that these can in principle be plant-based (i.e. vegan).

[0105] Also envisaged are pharmaceutical and nutraceutical applications. In one embodiment, a cold water-soluble, thermoreversible starch is used in a drug delivery systems. Thermoreversible gels are ideal for controlled release formulations. They can be used in oral suspensions wherein one or more drug(s) is / are suspended in a gel at room temperature but becomes liquid when warmed, ensuring proper delivery and ease of administration. Also provided is a topical gel which can be applied in a gel form and revert to liquid when warmed by body heat, allowing for easier spread and absorption.

[0106] As such, the disclosure also relates to compositions of the invention for use as a medicament. Furthermore, the disclosure pertains to a method of treating a subject, said method comprising the step of administering a composition of the invention to said subject. Additionally, the disclosure relates to the use of a composition of the invention in the manufacture of a medicament for the treatment of a disease in a subject.

[0107] Still further, the composition of the invention finds its use in a nutritional supplement where a thickened gel consistency enhances mouthfeel or helps with ease of ingestion, like instant meal replacements or protein gels. They can provide smooth, spreadable textures for skincare products. Other products that can benefit from including a cold water-soluble, thermoreversible starch as provided herein include cosmetics and personal care products, such as lotions, creams, hair gels and styling products. Thermoreversible gels help create products that remain stable at various temperatures but revert to liquid when exposed to body heat. These starches form stable gels that can be re-applied and reformed with heat or water, allowing for flexibility in hair styling.

[0108] Cold water-soluble, thermoreversible starches of the invention also have a range of industrial applications. Thermoreversible gelling starches can be used in adhesives that need to be reheated and reused, offering easy application and reformation of the adhesive properties. These starches can furthermore be used in textile processing, especially in warp sizing (coating of yarns), where temporary gel formation and reliquefaction can assist in improving yam smoothness and strength. Cold-soluble, thermoreversible starches can improve the strength, flexibility, and resilience of paper products and biodegradable packaging materials, especially those that require moisture resistance and need to reform after heating or cooling. Finally, the compositions of the invention can also be used in construction. Methods of manufacture

[0109] A further aspect of the invention relates to means and methods for providing a cold water soluble thermoreversible gelling starch composition as herein disclosed. As mentioned above, these can be manufactured in a sustainable and “green” fashion by subjecting native granular starch to a thermomechanical degradation process, preferably an extrusion process, to provide a composition having the specific molecular weight distribution and mass fractions Mwl and Mw2 as discussed herein above. In this process, the starting composition comprises a native granular starch comprising at least 55 wt%, preferably at least 60 wt%, more preferably at least 65 wt%, even more preferably at least 70 wt% of amylopectin. Preferably, the starting composition has a moisture content of 10 to 50 wt%, more preferably of from 15 to 35 wt%, even more preferably of from 18 to 30 wt%, relative to the total weight of the starting composition. Preferably, the starting composition has not been subjected to hydrolysis. More preferably, the starting composition has not been exposed to any (chemical or enzymatic) pretreatment. Preferably, the starting composition is free of any non-starch additives, more preferably free of any additives. In particular, it is preferred that the starting composition is free from starch-modifying agents, wherein preferably the starch-modifying agent is selected from the group consisting of crosslinkers, hydrolyzing agents, oxidizing agents, etherification agents, esterification agents, grafting agents, and phosphorylation agents. Furthermore, as used herein, “additives” preferably also includes catalysts. Consequently, it is preferred that the starting composition is substantially free of catalysts, and more preferably the starting composition is free of catalysts. As used herein, a “catalyst” is any substance that increases the reaction rate of the reaction between the starch and the starch-modifying agent, and it itself not consumed by the reaction.

[0110] Most preferably, the starting composition essentially consists of native granular starch and water, wherein the native granular starch has not been subjected to any pretreatment.

[0111] Preferably, in the methods of the invention no other substances are introduced into the extruder barrel than the starting composition, and optionally water, and optionally air. It will be understood that in the previous sentence, “in the methods of the invention” refers to immediately before starting extrusion, simultaneous with starting extrusion, and during extrusion. Accordingly, in one aspect the invention provides a method for providing a cold water soluble thermoreversible gelling starch composition according to the invention, wherein said method comprises the steps of: (i) providing a starting composition of a native granular starch comprising at least 55 wt% amylopectin, preferably at least 60 wt%, more preferably at least 65 wt%, even more preferably at least 70 wt%; wherein the average molecular weight of said native granular starch is indicated as MwO; and wherein the starting composition has a moisture content in a range of from 15 to 35 wt.% relative to the total weight of the starting composition; and wherein said starting composition has not been subjected to any pretreatment, and is preferably free of any non-starch additives, more preferably free of any additives; (ii) subjecting said starting composition to a thermomechanical degradation process, preferably an extrusion process, to convert said native granular starch to a blend of at least two mass fractions Mwl and Mw2 of different average molecular weight, in which a) Mw2 < Mwl < MwO; b) mass fraction Mwl has an average molecular weight of at most 80 % of MwO; c) the sum of the mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the blend; and d) the mass ratio between the mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1; and (iii) obtaining and optionally drying the starch blend and / or subjecting the starch blend to a step of particle size reduction.

[0112] According to the invention, native granular starch polymers are broken down by thermomechanical degradation under the combined influence of heat and mechanical stress to obtain precise ratios in chain lengths distributions as disclosed above wherein a small share of very short chains (mass fraction Mw2) is dispersed in a matrix of much longer chains (mass fraction Mwl). Heating starch can lead to gelatinization, where the crystalline structure disrupts, making it more soluble. If temperatures are too high, it can lead to depolymerization, breaking starch into smaller fragments or even glucose. Mechanical processing (like mixing, extrusion, or shear) can further promote degradation by physically breaking the starch chains. The applied force can lead to molecular scission, resulting in shorter chain lengths. In a method of the invention, heat and mechanical forces are applied simultaneously to synergistically enhance degradation. Granular starch as used herein refers to starch in its natural, unprocessed form, where it exists as discrete, microscopic granules. These starch granules are found in plant cells and are the way plants store energy. Common sources of granular starch include com, potatoes, wheat, rice, and cassava. In one embodiment, the starting composition comprises a native granular starch of a tuberous or a root origin. The source of tuber starch can provide a starch derived from any type of tuber. The term tuber, in the present context, is to be given its regular meaning, and refers to any type of tuber. In particular, tuber in the present definition includes structures which may also be called root. The term “tuber” as herein defined may thus be replaced with the phrase “root or tuber”. Preferably, a tuber in the present context is an edible tuber, which may be grown in the context of human food production. Tuber inherently comprises starch; preferred types of tuber are also rich in protein, such as tuber used for protein isolation. Tuber starch is understood to mean a starch from one type of tuber, although in special cases, tuber starch may comprise a mixture of starches derived from two or more types of tuber. Preferably, tuber in this context comprises potato (Solarium tuberosum), sweet potato (Ipomoea batatas), cassava (including Manihot esculenta, syn. M. utilissima, also called manioc, mandioca or yuca, and also including AT. palmata, syn. M. dulcis, also called yuca dulce), yam (Dioscorea spp), and / or taro (Colocasia esculenta). More preferably, the tuber comprises potato, sweet potato, cassava or yam, even more preferably the tuber comprises potato, sweet potato or cassava, even more preferably the tuber comprises a potato or sweet potato, and most preferably the tuber comprises potato (Solanum tuberosum).

[0113] Preferably, the native granular tuberous or root starch comprises at least 55 wt%, more preferably at least 60 wt%, even more preferably at least 65 wt%, more preferably still at least 70 wt%, preferably at least 72 wt%, more preferably at least 75 wt% amylopectin. Preferably, the native granular starch is selected from the group consisting of com starch, potato starch, tapioca starch, wheat starch, faba starch, pea starch, arrowroot starch, and combinations thereof; more preferably the native granular starch is potato starch, tapioca starch, pea starch, faba starch, or a combination thereof. In a preferred embodiment, the native starch is a waxy starch. The waxy starch is suitably selected from the group consisting of potato starch, tapioca starch, com starch, pea starch, faba starch, arrowroot starch, and any combination thereof. Most preferably, the waxy starch is waxy potato starch.

[0114] Preferably, the starting composition has a moisture content of 10 to 50 wt%, more preferably of from 15 to 35 wt%, even more preferably of from 18 to 30 wt%, relative to the total weight of the starting composition.

[0115] In a method of the invention, the starting composition typically has a moisture content of 10 to 50 wt%, preferably 15-35 wt%, relative to the total weight of the starting composition.

[0116] In some embodiments, the moisture content of the starting composition is at least 11 wt%, at least 12 wt%, at least 13 wt%, at least 14 wt%, at least 15 wt%, 16 wt%, at least 17 wt%, at least 18 wt%, at least 19 wt%, at least 20 wt%, at least 22 wt%, at least 24 wt% and / or up to 45 wt%, up to 42 wt%, up to 40 wt%, up to 38 wt%, up to 36 wt%, up to 35 wt%, up to 33 wt%, up to 30 wt%, up to 29 wt%, up to 28 wt%, up to 26 wt% relative to the total weight of the starting composition. Exemplary preferred ranges include 18-30 wt%, 18-28 wt%, 18-27 wt%, 20-30 wt%, 20-26 wt% and 20-24 wt%.

[0117] In one aspect, thermomechanical degradation step (ii) comprises extrusion, preferably single-step extrusion, and collecting the extrudate to obtain the cold-water soluble thermoreversible gelling starch.

[0118] An extrusion setup to obtain a cold water soluble thermoreversible gelling starch composition of the invention preferably comprises an extruder comprising a barrel section comprising at least 3 blocks, preferably at least 5 blocks, the first block of the barrel section comprising a feed inlet adapted for feeding the feed composition into the extruder, the second block, located downstream of the first block of the barrel section, comprising a water inlet adapted for introducing water and / or steam into the extruder, and one or more further downstream blocks adapted to setting the temperature along the barrel section to comprise an increasing temperature gradient, said extruder further comprising a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section.

[0119] The first block in the barrel section comprises a feed inlet, adapted for feeding a feed composition as herein defined into the extruder. The second block in the barrel section, located downstream of the first block, comprises a water inlet, adapted for introducing water and / or steam into the extruder so as to attain the desired moisture content of between 15 and 35 wt.%, preferably between 20 and 30 wt.%, based on the total weight of the composition. The first and the second block are preferably operated under more or less ambient conditions (20 - 30 °C). One or more further downstream blocks in the barrel section are preferably equipped with means for heating and cooling, so as to allow for setting the temperature along the barrel section to comprise an increasing temperature gradient. In preferred embodiments, the temperature increases stepwise to a maximum temperature of 100 - 250 °C, more preferably 130 - 180 °C, even more preferably 140 - 160 °C.

[0120] Although the barrel section must comprise an increasing temperature gradient, it is conceivable that in some setups, the barrel section may comprise one or more barrel parts in which there is a decreasing temperature gradient, or a constant temperature. Such barrel parts may be combined with for example one, two or more barrel parts with an increasing temperature gradient, as the skilled person appreciates.

[0121] The barrel section furthermore comprises a die section located downstream of the barrel section, and one or more screw elements adapted to convey the feed composition through the barrel section to the die section. In preferred embodiments, the barrel section is equipped with a co-rotating twin screw. Further preferably, the screw configuration comprises reversed pitch elements and conveying elements, preferably alternatingly. In further preferred embodiments, the screw configuration comprises 2 - 10 reversed pitch elements. Reversed pitch elements are preferably located of from 10 D to 20 D. In much preferred embodiments, a reversed pitch element, preferably the reversed pitch element is followed downstream by a kneading block, preferably having a stagger angle of between 30 and 60°, most preferably between 30 and 45°. In further preferred embodiments, the die section comprises a die having one, or two or multiple outlets, preferably one or two outlets, through which outlet(s) the extruded feed mass exits the extruder.

[0122] Extrusion conditions for obtaining the instant thermoreversible starches of the invention preferably comprise a temperature in the barrel section of 110 - 220 °C, more preferably 120 - 180 °C, even more preferably 140 - 165 °C. This value refers to the maximum temperature observed in a temperature gradient. Alternatively or additionally, the conditions comprise a pressure at the die, i.e. after the screw before the die of 4 - 50 bar, preferably 10 - 40 bar; and / or a specific mechanical energy (SME) of 0.08 - 0.25 kWh / kg, preferably 0.10-0.22 kWh / kg, more preferably 0.10 - 0.20 kWh / kg.

[0123] During extrusion, a composition is formed that is herein referred to as the “extrusion mass” or “melt”. Preferably, the moisture content of the extrusion mass is in a range of from 15 to 50 wt%, relative to the total weight of the extrusion mass, more preferably of from 18 to 40 wt%, even more preferably of from 19 to 30 wt%, and most preferably of from 20 to 27 wt%. Preferably, the temperature of the extrusion mass at the die of the extruder is in a range of from 120 to 180 °C, more preferably of from 125 to 170 °C, and most preferably of from 130 to 165 °C.

[0124] As the skilled person is aware, some parameters, such as the throughput and the screw speed, may depend on the type of extruder and screws used. The skilled person is able to recalculate the values for these parameters for other types of extruder. For example, typically for a small extruder, the extruder can be operated at 100 - 1800 screw rotations per minute (rpm), preferably 200 - 1250 rpm, more preferably 250 - 900 rpm; alternatively, the extruder can preferably be operated at 250 - 1600 rpm. Higher rotation speeds, such as 500 - 1600 rpm, preferably 900 - 1500 rpm, provide for higher throughput and hence improved production efficiency. Likewise, also typical for a small extruder is a throughput of about 10-100 kg / h.

[0125] In an exemplary embodiment, the extruder can be a ZSK 27 extruder (a co-rotating twin-screw extruder marketed by Coperion). In this particular embodiment, further described in the examples, the extruder comprises 6 blocks, having a total length of 24D. The diameter D of the screws is 27 mm. The barrel section, and thus the screws, have a total length of around 648 mm, and the screw diameter is 27 mm.

[0126] In this exemplary embodiment, the screw configuration comprises two reversed pitch elements alternatingly intertwined with conveying elements. The reversed pitch elements are preferably placed towards the end of the screw starting at position 18 D. The die section comprises two conical cavities, comprising cylindrically shaped die holes having a diameter of 3 mm and a length of 2 mm. In this particular embodiment, the temperature in the first (feeding) block and second (water addition) block can be more or less ambient. The third and fourth blocks are operated at a temperature of 50 - 100 °C, preferably 60 - 90 °C. The fifth and sixth blocks are operated at a temperature of 100 - 250 °C, preferably 130 - 180 °C, more preferably 140 - 160 °C. The throughput is 15 to 25 kg / h based on total weight (including moisture) and operated at 500 rpm. At higher rotation speed, the throughput can be higher, as the skilled person appreciates. The throughput can be 10 - 100 kg / h, preferably 15 - 80 kg / h. At 800 - 1600 rpm, the throughput can be 40 - 80 kg / h.

[0127] For example, the extrusion process is characterized by one or more of the following parameters:

[0128] (i) a temperature in a barrel section of the extruder in a range of from 100 to 250 °C, preferably of from 130 to 225 °C, more preferably of from 140 to 200 °C, most preferably of from 142 to 160 °C;

[0129] (ii) a die pressure (P) in a range of from 10 to 90 bar, preferably of from 10 to 70 bar, more preferably of from 15 to 40 bar; and / or

[0130] (iii) a specific mechanical energy (SME) of at least 0.05 kWh / kg, preferably an SME in a range of from 0.08 to 0.30 kWh / kg.

[0131] In one embodiment, native granular starch which has not been exposed to any prior hydrolysis step is subjected to extrusion at a temperature of 110 - 220 °C, a pressure of 4 - 50 bar and a torque of 15 - 65 %, said temperature, pressure and torque collectively providing a specific mechanical energy (SME) of 0.08 - 0.25 kWh / kg, said extrusion being executed at a moisture content of from 10 to 50 wt%, preferably from 15 to 35 wt%, more preferably 18 - 30 wt.%, relative to the total weight of the melt.

[0132] Using the described starting (feed) composition and the extrusion process described above, a starch composition of the invention having cold-water soluble and thermoreversible properties can generally be obtained.

[0133] Thus, in one aspect a method of the invention comprises a) providing a native granular starch; b) subjecting said native granular starch without a prior hydrolysis step to extrusion at a temperature of 110 - 220 °C, a pressure of 4 - 50 bar and a torque of 15 - 65 %, said temperature, pressure and torque collectively providing a specific mechanical energy (SME) of 0.08 - 0.25 kWh / kg, said extrusion being executed at a moisture content of from 10 to 50 wt%, preferably from 15 to 35 wt%, more preferably 18 - 30 wt.%, relative to the total weight of the melt; c) collecting the extrudate to obtain the cold-water soluble thermoreversible gelling starch; and d) optionally, subjecting the cold-water soluble thermoreversible gelling starch to a step of drying and / or to a step of particle size reduction.

[0134] The thermomechanical degradation (e.g. extrusion) process can be carefully monitored e.g. by molecular weight analysis, to ensure that the granular starch is degraded to a degree that it provides a composition having the specific molecular weight distribution discussed herein above.

[0135] As is exemplified herein below, it was found that when using extrusion for thermomechanical starch degradation, the extent of starch degradation (reflected e.g. by the molecular weight distribution) is directly related to extrusion conditions. More in particular, the average molecular weight distribution and / or average poly dispersity could be directly linked to the parameter (herein also referred to as ‘’degradation factor”) SME / (P / T) (which can also be written as SME*T / P). Herein, SME (kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition, P (bar) is the pressure at the die of the extruder and T (°C) is the melt temperature at the die of the extruder.

[0136] After extensive testing and optimization of the extrusion conditions, it was found that cold water starch compositions having desired gelling properties can be obtained using extrusion settings wherein SME*T / P is in the range of from 0.30 to 4.50 kWh °C kg'1bar'1.

[0137] Therefore, in another aspect the invention pertains to a method for providing a cold- water soluble thermoreversible gelling starch composition according to the invention, wherein the method comprises the steps of (a) providing a starting composition of a native granular starch, wherein the native granular starch comprises amylopectin in an amount of at least 55 wt%, preferably at least 60 wt%, more preferably at least 65 wt%, and even more preferably at least 70 wt%; and wherein the starting composition has a moisture content in a range of from 10 to 50 wt%, preferably of from 15 to 35 wt.%, relative to the total weight of the starting composition; preferably said starting composition has not been subjected to any pretreatment; and preferably said starting composition is free of any non-starch additives, and more preferably free of any additives; (b) subjecting the starting composition to thermomechanical degradation by a single-step extrusion process characterized by a degradation factor defined as SME*T / P in a range of from 0.30 to 4.50 kWh °C kg'1bar'1, wherein SME (kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition; P (bar) is the pressure at the die of the extruder; T (°C) is the melt temperature at the die of the extruder; and (c) obtaining and optionally drying the extrudate and / or subjecting the extrudate to a step of particle size reduction. All aforementioned preferences, values, parameters regarding the other method of the invention may also apply to the method of this further aspect.

[0138] In some embodiments, the extrusion process is characterized by SME*T / P of at least 0.30, at least 0.32, at least 0.35, at least 0.40, at least 0.45, at least 0.50, at least 0.60, at least 0.70, at least 0.80, at least 0.90, at least 1.00, or at least 1.10 kWh °C kg'1bar'1and / or up to 4.40, up to 4.30, up to 4.20, up to 4.10, up to 4.00, up to 3.80, up to 3.60, up to 3.40, up to 3.20, up to 3.00, up to 2.90, up to 2.80, up to 2.70, up to 2.60, up to 2.50, up to 2.40, up to 2.20, up to 2.10, up to 2.00, up to 1.90, up to 1.85, up to 1.80, up to 1.75, up to 1.70, up to 1.65, up to 1.60, up to 1.55, up to 1.50, up to 1.40, up to 1.35 or up to 1.30 kWh °C kg'1bar'1. Exemplary ranges include 0.30 to 3.00 kWh °C kg'1bar'1, 0.30 to 2.50 kWh °C kg'1bar'1, 0.30 to 1.50 kWh °C kg'1bar'1, and 0.30 to 1.00 kWh °C kg'1bar'1.

[0139] Also provided herein is a cold water soluble thermoreversible gelling starch composition obtainable or obtained by a method according to the invention.

[0140] List of Clauses

[0141] Clause 1. A cold-water soluble thermoreversible gelling starch composition comprising at least two mass fractions Mwl and Mw2 of different average molecular weight, in which a) Mw2 < Mwl < MwO, MwO being defined as the average molecular weight of the native granular starch from which the cold-water soluble thermoreversible gelling starch composition was prepared; b) mass fraction Mwl has an average molecular weight of at most 80 % of MwO; c) the sum of the mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the cold-water soluble thermoreversible gelling starch composition; and d) the mass ratio between the mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1.

[0142] Clause 2. The starch composition according to Clause 1, wherein Mw2 has an average molecular weight in a range of from 0.2 to 60 % of MwO.

[0143] Clause 3. The starch composition according to Clause 1 or 2, wherein the native granular starch from which said composition was prepared comprises:

[0144] (i) a waxy potato starch, characterized by an MwO of 100 000 kDa ± 10 000 kDa, preferably about 100 223 kDa;

[0145] (ii) a native potato starch, characterized by an MwO of 450 000 kDa ± 45 000 kDa, preferably about 443 847 kDa; and / or

[0146] (iii) a waxy tapioca starch, characterized by an MwO of 270 000 kDa ± 27 000 kDa, preferably about 270 000 kDa.

[0147] Clause 4. The starch composition according to any one of Clauses 1-3, wherein mass fraction Mwl has an average molecular weight in a range of from 13 000 to 35 000 kDa; preferably of from 17 000 to 32 000 kDa.

[0148] Clause 5. The starch composition according to any one of the preceding Clauses, wherein mass fraction Mw2 has an average molecular weight in a range of from 700 to 3000 kDa; preferably of from 750 to 2500 kDa.

[0149] Clause 6. The starch composition according to any one of the preceding Clauses, having an average poly dispersity in a range of from 1.6 to 5.0, preferably of from 2.2 to 4.8, more preferably of from 2.2 to 4.4. Clause 7. The starch composition according to any one of the preceding Clauses, wherein mass fractions Mwl and Mw2 together constitute at least 80 wt% of the dry weight of the composition; preferably at least 85 wt%, more preferably at least 90 wt%, even more preferably at least 95 wt%, and most preferably at least 99 wt% of the dry weight of the composition.

[0150] Clause 8. The starch composition according to any one of the preceding Clauses, wherein said composition comprises or consists of starch components that have not been chemically modified.

[0151] Clause 9. The starch composition according to any one of the preceding Clauses, wherein both mass fractions Mwl and Mw2 comprise a waxy starch selected from the group consisting of corn starch, potato starch, tapioca starch, wheat starch, faba starch, pea starch, arrowroot starch, and combinations thereof; wherein preferably the waxy starch is potato starch, tapioca starch, or a combination thereof; and most preferably the waxy starch is potato starch.

[0152] Clause 10. A food item, a feed item, a thickening agent, an adhesive, a cosmetic product, paper, or a construction material, comprising a cold-water soluble thermoreversible gelling starch composition according to any one of the preceding Clauses.

[0153] Clause 11. The use of a cold-water soluble thermoreversible gelling starch composition according to any one of Clauses 1 to 9 as a food ingredient, a feed ingredient, a thickening agent, an adhesive, an ingredient for a cosmetic product, a gelling agent, a pectin replacer, a gelatin replacer, as an ingredient for the production of paper, and / or as a component of a construction material.

[0154] Clause 12. A method for providing a cold-water soluble thermoreversible gelling starch composition according to any one of Clauses 1 to 9, wherein said method comprises the steps of: (i) providing a starting composition of a native granular starch comprising at least 60 wt% amylopectin, preferably at least 65 wt% amylopectin, more preferably at least 70 wt% amylopectin; wherein the average molecular weight of said native granular starch is indicated as MwO; and wherein the starting composition has a moisture content in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of the starting composition; and wherein said starting composition has not been subjected to any pretreatment, and is preferably free of any non-starch additives, more preferably free of any additives;

[0155] (ii) subjecting said starting composition to a thermomechanical degradation process, preferably an extrusion process, to convert said native granular starch to a blend of at least two mass fractions Mwl and Mw2 of different average molecular weight, in which a) Mw2 < Mwl < MwO; b) mass fraction Mwl has an average molecular weight of at most 80 % of MwO; c) the sum of the mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the blend; and d) the mass ratio between the mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1 ; and

[0156] (iii) obtaining and optionally drying the blend and / or subjecting the starch blend to a step of particle size reduction.

[0157] Clause 13. The method according to Clause 12, wherein step (ii) comprises single- step extrusion.

[0158] Clause 14. A method for providing a cold-water soluble thermoreversible gelling starch composition according to any one of Clauses 1 to 9, wherein the method comprises the steps of: (a) providing a starting composition of a native granular starch, wherein the native granular starch comprises amylopectin in an amount of at least 60 wt%, preferably at least 65 wt%, and more preferably at least 70 wt%; and wherein the starting composition has a moisture content in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of the starting composition; preferably wherein said starting composition has not been subjected to any pretreatment; and preferably wherein said starting composition is free of any nonstarch additives, and more preferably free of any additives;

[0159] (b) subjecting the starting composition to thermomechanical degradation by a single-step extrusion process characterized by a degradation factor defined as SME*T / P in a range of from 0.30 to 4.50 kWh °C kg'1bar'1, wherein

[0160] SME (kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition

[0161] T (°C) is the melt temperature at the die of the extruder

[0162] P (bar) is the pressure at the die of the extruder; and

[0163] (c) obtaining and optionally drying the extrudate and / or subjecting the extrudate to a step of particle size reduction.

[0164] Clause 15. The method according to Clause 14, wherein the degradation factor is in a range of from 0.35 to 3.0 kWh °C kg'1bar'1, preferably of from 0.40 to 2.50 kWh °C kg'1bar'1, more preferably of from 0.50 to 2.00 kWh °C kg'1bar'1.

[0165] Clause 16. The method according to any one of Clauses 12 to 15, wherein the extrusion process is characterized by one or more of the following parameters:

[0166] (i) a temperature in a barrel section of the extruder in a range of from 100 to 250 °C, preferably of from 130 to 225 °C, more preferably of from 140 to 200 °C, most preferably of from 142 to 160 °C;

[0167] (ii) a die pressure (P) in a range of from 1 to 90 bar, preferably of from 10 to 70 bar, more preferably of from 15 to 40 bar;

[0168] (iii) a specific mechanical energy (SME) of at least 0.05 kWh / kg, preferably an SME in a range of from 0.08 to 0.30 kWh / kg; and / or (iv) a moisture content of the melt in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of said melt.

[0169] Clause 17. The method according to any one of Clauses to 12 to 16, comprising subjecting said native granular starch without a prior hydrolysis step to an extrusion process, wherein the extrusion process is performed at a melt temperature in a range of from 110 to 220 °C, a pressure in a range of from 4 to 50 bar, and a torque in a range of from 15 to 65%; said temperature, pressure and torque collectively providing a specific mechanical energy (SME) in a range of from 0.08 to 0.30 kWh / kg; and wherein the moisture content of the melt is in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of said melt.

[0170] Clause 18. The method according to any one of Clauses to 12 to 17, wherein said starting composition has a moisture content in a range of from 18 to 30 wt%, preferably of from 20 to 28 wt.%, relative to the total weight of the starting composition.

[0171] Clause 19. A cold-water soluble thermoreversible gelling starch composition obtainable by a method according to any one of Clauses 12 to 18.

[0172] EXAMPLES

[0173] The invention is illustrated below using several examples. It will be understood that the invention is not limited thereto, and other embodiments such as those listed above are also capable of achieving the technical effects and benefits of the invention. In particular, the starting materials and extrusion conditions used in the examples are not limiting, and the specification indicates other suitable materials and conditions.

[0174] Example 1 - Obtaining degraded starch by extrusion

[0175] Equipment

[0176] A ZSK27 Coperion twin-screw, co-rotating, self-wiping extruder was used which had three peripherals attached to it: a water pump gravimetric feeder (Feeder 1), a solid material gravimetric feeder (Feeder 2) and a centric pelletizer (1 or 3 blades) provided with a compressed air outlet. The extruder barrel was composed of 6 modular blocks having a total length of 24D (4D x 6). The diameter D of the screws was 27 mm. The screws had a total length of around 648 mm. For samples 1-12 in Table 6 below, the die plate used presented conical cavities that ended into cylindrical die holes having a diameter of 3 mm and a length of 2 mm. For samples 13 and 14 in Table 6 below, die plate used presented one conical cavity that ended into a cylindrical die hole having a diameter of 3 mm and a length of 2 mm.

[0177] The die configurations were indicated as nx(DxL), where n stands for the total number of holes, D stands for the Diameter of the holes and L stands for the Length of the holes. The solids were fed at 2D, the water inlet was placed at 9D. The pelletizer blades distance to the die was set as close to the die holes as possible ( < 1 mm).

[0178] Extrudates were milled to the required particle size with a hammer-mill over selected sieves (1 and 0.5 mm). Detailed information regarding equipment used is available in Table 1 below. Table 1. Equipment used for extrusion and milling. The screw configuration designs used were as described in Table 2 A (configuration S. l), Table 2B (configuration S.2), and Table 2C (configuration S.6). In said Tables, C stands for Conveying, K45 stands for Kneading at 45° stagger angle, P stands for Positively conveying elements, N stands for Negatively conveying elements and all elements are defined with element length over pitch length eL / pL. At 18.89D (or 510mm) S. l has a CP while S.2 has a CN. So, S.l has 1 negative element and S.2 has 2 negative elements. Thus, S.2 applies more shear / rpm.

[0179] Table 2A. Screw configuration design S.1.

[0180] Table 2B. Screw configuration design S.2.

[0181] Table 2C. Screw configuration design S.6.

[0182] Barrel block settings and starting materials

[0183] The temperature (T) profiles of the barrel block was set as shown in Tables 3 and 4 below, with set temperature profile I used for samples 1-12 of Table 6 below, and set temperature profile II for samples 13 and 14 of Table 6. The temperature of block 1 (feeding block) was not controlled, and is hence indicated with “NA” in Tables 3 and 4. For both set temperature profiles, blocks 2 to 6 were controlled via automatic electrical heating and water cooling.

[0184] Table 3. Temperature settings of the barrel blocks for samples 1-12. Table 4. Temperature settings of the barrel blocks for samples 13 and 14.

[0185] The native granular starches that are subjected to extrusion in these Examples are indicated in Table 5. Table 5. Starches used in the experiments. Other starches are also suitable.

[0186] Extrusion procedure

[0187] Untreated and unmodified raw materials (WPS; WTS; NFS; NPES) and drinkable water were fed to the extruder and thermomechanically processed according to the settings indicated in Table 6. Therein, SME (kWh / kg) is the specific mechanical energy transferred from the extruder to the starting composition, P (bar) is the pressure at the die of the extruder, T (°C) is the melt temperature at the die of the extruder, and the moisture content refers to the water content of the melt during extrusion as compared to the total weight of said melt. The resulting pelletized extrudates (with 1 blade at 3000 rpm) were collected and stored on metal plates to let them cool down and release excess moisture overnight. The following day, extrudates were hammer milled in two steps (through 1 mm and 0.5 mm sieves, at 3.5 rotational speed setting).

[0188] Table 6. Starches and extrusion settings used for samples 1-14.

[0189] *A = lx(3x2), S.2; B = 2x(3x2), S.2; C = 2x(3x2), S.l; D = lx(3x2), S.6.

[0190] Example 2 - Molecular weight characterization of thermomechanically degraded starch

[0191] Extrudates 1-14 as obtained in Example 1 were analyzed as described below. The results of these analyses are shown in Table 7 A (extrudates 1-12) and Table 7B (extrudates 13 and 14) below. Therein, the average molecular weight (Mw) refers to the weight average molecular weight and Dn refers to the polydispersity. Unless reference is made to mass fraction 1 (Fxl), mass fraction 2 (Fx2), or mass fraction 3 (Fx3), the average values provided in Tables 7A and 7B relate to the extrudate as a whole.

[0192] As a reference, the average molecular weights (Mw avg.) of raw materials were 100 223 kDa for WPS; 270 000 kDa for WTS; 152 000 kDa for NFS; and 328 000 kDa for NPES. Example 2.1 - Analysis of extrudates 1-12

[0193] Extrudates 1-12 obtained in Example 1 were subjected to molecular weight analysis. Molecular weight analyses were performed by size exclusion chromatography (SEC) with multi-angle laser light scattering (MALLS) and refractive index detection (RI). A Shodex-OHpakSB-804 HQ column was used with 50 nM NaNCh as eluent. Detection was performed with a multiangle laser light scattering photometer (type Dawn Heleos II, 18 angles, Wyatt Technology) with a refractive index detector (Optilab T-rEx-658 nm, Wyatt Technology). Data were evaluated by the Berry equation method, second order fit and second virial coefficient (A2=0). The refractive index increment dn / dc was 0.148 ml / g and these measurements were performed at 25 °C.

[0194] A specific amount (~60 mg) of a sample (powder, as is) was dissolved with a 20 ml of eluent (50 nM NaNCh) at 130°C for 20 minutes. The sample was continuously stirred in a glass vial and the vial was capped with an aluminum / silicone septum. The solution was filtered through 5.0 pm cellulose acetate filter before injection on the SEC.

[0195] Example 2.2 - Analysis o f extrudates 13 and 14

[0196] For extrudates 13 and 14 as obtained in Example 1, analyses were performed using Asymmetric Flow Field Flow Fractionation with Multi-Angle Laser Light Scattering and Refractive Index Detection (FFF(AF4) / MALLS / RI) and Size Exclusion Chromatography (SEC). The Eclipse AF4 system was equipped with a frit inlet channel (FI) and regenerated cellulose with a pore size of lOkDa (LOxlO4g / mol). Molecules with a molecular mass smaller than lOkDa (including salts) are washed away over the membrane. Elution was performed using a 50 mM NaNCh (aq) eluent. The Shodex OHpak SB-804 HQ SEC column was used. This column can separate molecules with a molecular weight ranging from 5xl03to 1x10® Da. Detection was performed using a multi-angle laser light scattering photometer (Dawn Heleos II, 18 angles, Wyatt Technology) and a refractive index detector (Optilab T-rEx, 658 nm, Wyatt Technology). The data were evaluated using the Berry equation method with a second- order fit and a second-virial coefficient of A2 = 0. The refractive index increment, dn / dc, was 0.148 ml / g, and these measurements were performed at 25 °C.

[0197] A specific amount (50 mg) of a defatted sample (powder (as is)) was dissolved with a 20 ml of eluent (50 mM NaNOs) at 130°C for 30 minutes. The sample was continuously stirring in a glass vial and the vial was capped with an aluminum / silicone septum. The solution was filtered through 5.0 pm cellulose acetate filter before injection on the FFF / SEC. Table 7A. Results from molecular weight analysis of extrudates 1-12.

[0198] Table 7B. Results from molecular weight analysis of extrudates 13 and 14. Example 3 - Thermoreversible gelling using degraded starch

[0199] Example 3.1 - Thermor ever sible selling of extrudates 1-12 of Example 1 Extrudates 1-12 obtained in Example 1 were evaluated for thermoreversibility by preparing gels and treating them with multiple steps of heating and cooling. To that end, solutions at 15% and 35% w / w in demineralized water were prepared by stirring at room temperature and then heated to boiling in a water bath for 5-10 minutes. The solutions were then stored overnight in a fridge at 4-7 °C. The formed gels were reheated in a water bath for 5 to 10 minutes and loss of viscosity was observed until transparent viscous liquid-like gels to thin liquid-like gels were observed. A cooling step was then repeated overnight in the fridge and solid gels could be observed the day after.

[0200] Rheology tests were performed on a selection of samples, especially with the aim to compare WPS and WTS based TRES gels. Gels at 25% w / w in demineralized water of TRES samples (1, 6, 10, 12) were prepared by stirring for 5-10 minutes. The weight of the extrudate powder was calculated based on the powder moisture content. The total mass of the solution was set to be 25 grams. Subsequently, the suspension was stirred and heated until boiling in a water bath for approximately 10 minutes. The solution thus obtained was then poured into a capped container and stored in the fridge at 4-7°C overnight to form a solid gel to be tested on a rheometer.

[0201] Rheological measurements were executed with a 50 mm parallel plate geometry at a gap of 1000 pm in the Anton Paar Rheometer (MCR-302) from RheoCompass (Austria, Europe). Samples were loaded onto the rheometer plate and excess sample was removed using a spatula. Paraffin oil was used to prevent evaporation during the measurement. The experiments were carried out at a heating rate of 5°C / min. Strain for the measurements at 1% is selected to ascertain the thermal equilibration of the samples and to be within the linear viscoelastic (LVE) region. Dynamic temperature sweeps (40- 90 °C) were performed at a fitting strain rate and angular frequency (1 rad / s) to investigate the effect of temperature on storage modulus (G') and loss modulus (G") of the material.

[0202] Variations in absolute values of viscosity plus an inversion of the G’ and G” between 45 to 75 °C (with observable shift of melting point) were observed for all samples tested. See Figure 1 for exemplary extrudates 1, 7, and 12. These results confirmed already observed thermoreversibility and indicate that extrusion conditions and molecular weight influenced gel strength (viscosity both at low and high temperature) and melting point. Example 3.2 - Thermoreversible gelling of extrudates 13 and 14 of Example 1

[0203] The thermoreversible gelling properties of the extrudates samples 13 and 14 as obtained in Example 1 were determined with a rapid visco-analyzer (RVA Super 4 Newport Scientific (serial no. 2041657). Aqueous solutions of extrudates 13 and 14 were separately prepared using demineralized water to obtain a dry matter content of 15 wt% based on the total weight of the solution. The settings for the RVA method are described in Table 8 below. In these analyses, two consecutive cycles of a temperature scan were performed to check on thermoreversibility. The results are shown in Table 9.

[0204] Table 8. Settings for the rapid visco-analyzer analyzing extrudates 13 and 14.. Table 9. Results of the rapid visco-analyzer analyses of extrudates 13 and 14..

[0205] STote: An increase of viscosity is observed from 1stto 2ndcycle, which can be attributed to an increase in sample concentration due to water evaporation, being the RVA cups used open to air.

[0206] Example 4 - Cold water solubility and application in panna cotta

[0207] The extrudates obtained in Example 1 showed quick cold water solubility, instantly dissolving in water at room temperature (20-25 °C) while stirring, both in demineralized and drinking water, forming clear solutions. Extrudates 1-12 were tested at concentrations between 5% to 35% w / w, and extrudates 13 and 14 at 15% w / w. All tested concentrations gave the desired result of quick cold water solubility.

[0208] To demonstrate one of the many possible applications of the extrudates obtained in Example 1, extrudates 1-12 were used to prepare panna cotta. In particular, the aim was to reproduce the gelling behavior of classic gelatin by using an extrudate obtained in Example 1. The ingredients are shown in Table 10.

[0209] Table 10. Ingredients used for making panna cotta.

[0210] Panna Cotta preparation with classic gelatin requires soaking of gelatine and heating while mixing with other ingredients. To prepare a one-to-one comparison, soy whipping cream, sugar and one of extrudates 1-12 obtained in Example 1 were mixed in the amounts shown in Table 10. Mixing was performed at room temperature (about 20- 25 °C). A homogenous mix was easily obtained at room temperature without formation of lumps for all extrudates used. The mix was subsequently heated to boiling while stirring (in a 100 ml beaker in a water bath, constantly stirred at 600-800 rpm with a magnetic stirrer). The mix was poured into a small plastic container which was sealed with a lid and stored in a fridge overnight at 4-7 °C. Texture of the gels was inspected visually and tested by scooping the gels with a tea spoon.

[0211] A variety of textures was obtained, as shown in Table 11 below. The meaning of the quality score in Table 11 is shown in Table 12.

[0212] Table 11. Results from the panna cotta tests using extrudates 1-12. The third column provides a value for the degradation factor divided by the average polydispersity of the extrudate. Table 12. Scoring method used to assign the score provided in Table 11.

[0213] Based on extrusion conditions, it was possible to obtain a variety of textures (smooth firm gels, smooth soft gels, irregular soft gels). In particular, a correlation between extrusion conditions and firmness could be observed. While firm and smooth gels are preferred for panna cotta, gels with other textures and / or surfaces (i.e. having a lower score in Table 12) find their use in other applications such as, but not limited to, the preparation of ricotta cheese, yoghurt, creams, custards, and the like.

Claims

Claims1. A cold-water soluble thermoreversible gelling starch composition comprising at least two mass fractions Mwl and Mw2 of different average molecular weight, in which a) Mw2 < Mwl < MwO, MwO being defined as the average molecular weight of the native granular starch from which the cold-water soluble thermoreversible gelling starch composition was prepared; b) mass fraction Mwl has an average molecular weight of at most 80 % of MwO; c) the sum of the mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the cold-water soluble thermoreversible gelling starch composition; and d) the mass ratio between the mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1.

2. The starch composition according to claim 1, wherein Mw2 has an average molecular weight in a range of from 0.2 to 60 % of MwO.

3. The starch composition according to claim 1 or 2, wherein the native granular starch from which said composition was prepared comprises:(i) a waxy potato starch, characterized by an MwO of 100 000 kDa ± 10 000 kDa, preferably about 100 223 kDa;(ii) a native potato starch, characterized by an MwO of 450 000 kDa ± 45 000 kDa, preferably about 443 847 kDa;(iii) a waxy tapioca starch, characterized by an MwO of 270 000 kDa ± 27 000 kDa, preferably about 270 000 kDa;(iv) a native faba starch, characterized by an MwO of 150 000 kDa ± 15 000 kDa, preferably about 152 000 kDa; and / or(v) a native pea starch, characterized by an MwO of 330 000 ± 33 000 kDa, preferably about 328 000 kDa.

4. The starch composition according to any one of the preceding claims, wherein mass fraction Mwl has an average molecular weight in a range of from 12 000 to 36 000kDa, preferably of from 13 000 to 35 000 kDa; more preferably of from 17 000 to 32 000 kDa.

5. The starch composition according to any one of the preceding claims, wherein mass fraction Mw2 has an average molecular weight in a range of from 700 to 3000 kDa; preferably of from 750 to 2500 kDa.

6. The starch composition according to any one of the preceding claims, having an average poly dispersity in a range of from 1.4 to 6.2, preferably of from 1.5 to 6.0, more preferably of from 1.6 to 5.0, more preferably still of from 2.2 to 4.8, and even more preferably of from 2.2 to 4.4.

7. The starch composition according to any one of the preceding claims, wherein mass fractions Mwl and Mw2 together constitute at least 80 wt% of the dry weight of the composition; preferably at least 85 wt%, more preferably at least 90 wt%, even more preferably at least 95 wt%, and most preferably at least 99 wt% of the dry weight of the composition.

8. The starch composition according to any one of the preceding claims, wherein said composition comprises or consists of starch components that have not been chemically modified.

9. The starch composition according to any one of the preceding claims, wherein both mass fractions Mwl and Mw2 comprise a starch selected from the group consisting of corn starch, potato starch, tapioca starch, wheat starch, faba starch, pea starch, arrowroot starch, and combinations thereof; wherein preferably the starch is potato starch, tapioca starch, pea starch, faba starch, or a combination thereof; more preferably the starch is waxy potato starch, waxy tapioca starch, or a combination thereof; and most preferably the starch is waxy potato starch.

10. A food item, a feed item, a thickening agent, an adhesive, a cosmetic product, paper, or a construction material, comprising a cold-water soluble thermoreversible gelling starch composition according to any one of the preceding claims.

11. The use of a cold-water soluble thermoreversible gelling starch composition according to any one of claims 1 to 9 as a food ingredient, a feed ingredient, a thickening agent, an adhesive, an ingredient for a cosmetic product, a gelling agent, a pectin replacer, a gelatin replacer, as an ingredient for the production of paper, and / or as a component of a construction material.

12. A method for providing a cold-water soluble thermoreversible gelling starch composition according to any one of claims 1 to 9, wherein said method comprises the steps of:(i) providing a starting composition of a native granular starch comprising at least 55 wt% amylopectin, preferably at least 60 wt% amylopectin, more preferably at least 65 wt% amylopectin, even more preferably at least 70 wt% amylopectin; wherein the average molecular weight of said native granular starch is indicated as MwO; and wherein the starting composition has a moisture content in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of the starting composition; and wherein said starting composition has not been subjected to any pretreatment, and is preferably free of any non-starch additives, more preferably free of any additives;(ii) subjecting said starting composition to a thermomechanical degradation process, preferably an extrusion process, to convert said native granular starch to a blend of at least two mass fractions Mwl and Mw2 of different average molecular weight, in which a) Mw2 < Mwl < MwO; b) mass fraction Mwl has an average molecular weight of at most 80 % of MwO; c) the sum of the mass fractions Mwl and Mw2 represents at least 50 wt.% of the total weight of the blend; and d) the mass ratio between the mass fractions Mwl and Mw2 is in a range of from 1.1 : 1 to 20 : 1 ; and(iii) obtaining and optionally drying the blend and / or subjecting the starch blend to a step of particle size reduction.

13. The method according to claim 12, wherein step (ii) comprises single-step extrusion.

14. A method for providing a cold-water soluble thermoreversible gelling starch composition according to any one of claims 1 to 9, wherein the method comprises the steps of:(a) providing a starting composition of a native granular starch, wherein the native granular starch comprises amylopectin in an amount of at least 55 wt%, preferably at least 60 wt%, more preferably at least 65 wt%, and even more preferably at least 70 wt%; and wherein the starting composition has a moisture content in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of the starting composition; preferably wherein said starting composition has not been subjected to any pretreatment; and preferably wherein said starting composition is free of any non-starch additives, and more preferably free of any additives;(b) subjecting the starting composition to thermomechanical degradation by a single-step extrusion process characterized by a degradation factor defined as SME*T / P in a range of from 0.30 to 4.50 kWh °C kg'1bar'1, whereinSME (kWh / kg) is the specific mechanical energy transferred from the extruder to the starting compositionT (°C) is the melt temperature at the die of the extruderP (bar) is the pressure at the die of the extruder; and(c) obtaining and optionally drying the extrudate and / or subjecting the extrudate to a step of particle size reduction.

15. The method according to claim 14, wherein the degradation factor is in a range of from 0.35 to 3.0 kWh °C kg'1bar'1, preferably of from 0.40 to 2.50 kWh °C kg'1bar'1, more preferably of from 0.50 to 2.00 kWh °C kg'1bar'1.

16. The method according to any one of claims 12 to 15, wherein the extrusion process is characterized by one or more of the following parameters:(i) a temperature in a barrel section of the extruder in a range of from 100 to 250 °C, preferably of from 130 to 225 °C, more preferably of from 140 to 200 °C, most preferably of from 142 to 160 °C;(ii) a die pressure (P) in a range of from 1 to 90 bar, preferably of from 10 to 70 bar, more preferably of from 15 to 40 bar;(iii) a specific mechanical energy (SME) of at least 0.05 kWh / kg, preferably an SME in a range of from 0.08 to 0.30 kWh / kg; and / or(iv) a moisture content of the melt in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of said melt.

17. The method according to any one of claims to 12 to 16, comprising subjecting said native granular starch without a prior hydrolysis step to an extrusion process, wherein the extrusion process is performed at a melt temperature in a range of from 110 to 220 °C, a pressure in a range of from 4 to 50 bar, and a torque in a range of from 15 to 65%; said temperature, pressure and torque collectively providing a specific mechanical energy (SME) in a range of from 0.08 to 0.30 kWh / kg; and wherein the moisture content of the melt is in a range of from 15 to 35 wt.%, preferably of from 18 to 30 wt%, relative to the total weight of said melt.

18. The method according to any one of claims to 12 to 17, wherein said starting composition has a moisture content in a range of from 18 to 30 wt%, preferably of from 20 to 28 wt.%, relative to the total weight of the starting composition.

19. A cold-water soluble thermoreversible gelling starch composition obtainable by a method according to any one of claims 12 to 18.

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